1. Field of the Invention
This invention relates to a transmission, particularly for cross-country motor vehicles, which transmission comprises a multispeed change gear set comprising a plurality of loose spur gears, a plurality of fixed spur gears, each of which is permanently in mesh with one of the loose spur gears, and a second gear set, which is adapted to be selectively driven by said change gear set.
2. Description of the Prior Art
By means of said selectively operable gear set, which is always a speed-reducing transmission, the number of speeds provided by the change gear set can be doubled so that, e.g., the same number of speeds is available for the relatively slow cross-country travel as for road travel at relatively high speeds. The arrangement of the selectively operable gear set behind the multispeed change gear set affords the advantage that the change gear set may consist of lighter elements than in an arrangement in which the change gear set is preceded by a selectively operable gear set because the operation of the selectively operable gear set will not result in a change of the speeds of the gears of the change gear set, which speeds are relatively high so that only relatively low torques are required. In the previous transmissions of the present kind the change gear set comprises an input shaft and an output shaft and each of said shafts carries a fixed or a loose spur gear of the change gear set. Because each shaft carries a plurality of juxtaposed spur gears and interposed clutches, the transmission has a considerable dimension in the axial direction of the shafts. This is particularly undesirable in vehicles having an engine which extends transversely to the direction of travel and is directly adjoined by a change gear set in the direction of the crankshaft of the engine. The provision of the selectively operable gear set considerably increases the total structural expenditure involved in the transmission.